Such an apparatus for the longitudinal adjustment of a ski binding part is illustrated for example in FIGS. 10 to 14 of German Offenlegungsschrift No. 30 15 478. In this design, the guide rail is provided with perforations, into which engage downward projections of the locking element, which is urged toward the guide rail under the influence of the thrust springs. This is caused by sloped surfaces on the locking element which, when a ski shoe is not inserted into the skibinding part, engage corresponding sloped surfaces on the housing of the ski binding part. To release the locking engagement of locking element and guide rail, one leg of the approximately U-shaped locking element is lifted by means of an operating tool, which causes the projections of the locking element to come free from the perforations in the guide rail so that the ski binding part can be moved along the guide rail. However, this design has the disadvantage that the ski binding part must be constructed specially and that, during the adjusting operation, the locking element must constantly be held up manually, so that single-handed operation thereof is not possible.
A further apparatus for facilitating longitudinal adjustment of a ski binding part is disclosed in French Publication No. 24 51 756. In this apparatus, the locking element is also under the influence of a thrust spring and has projections which engage perforations in the guide rail. The locking element is, when no ski shoe is inserted, supported on a downwardly projecting part of the housing of the ski binding part. It is furthermore constantly coupled with a wire bar, the upper end area of which is stored in a recess of the ski binding part. For the longitudinal adjustment of the ski binding part, a special tool in the form of a screwdriver with two grooves arranged on the blade and directed toward its axis is required and can be placed under the wire bar, the locking element being lifted by pivoting the screwdriver 90.degree.. The ski binding part can subsequently be moved along the guide rail. When the desired position of the ski binding part is reached, then the screwdriver is turned back 90.degree. and thereafter pulled out from under the wire bar. The projections of the locking element then again engage, due to the urging of the thrust spring, the holes in the guide rail. However, this design has the disadvantages that the ski binding part must be constructed specially and that for its adjustment a special tool is needed.
A purpose of the invention is thus to provide an apparatus for facilitating the longitudinal adjustment of a ski binding part which does not have the disadvantages of conventional designs, which can be used in ski bindings of any construction, which is simple in structure and reliable in operation, and which can be operated with one hand and without any special tool.